Keira Knightley's Broadway debut disrupted by screaming fan

The 30-year-old actress had her opening preview performance of Therese Raquin at Studio 54, but was interrupted by a fan who began shouting at her. The NYPD confirmed to ET that the man was removed from the Broadway theater for unruly behavior, and is now under evaluation (a 5150 hold) at St. Luke's hospital.

The man began screaming at Keira almost as soon as the play started, an eyewitness tells E! News, shouting, "Keira, none of this is real! This is all an act! Christ was born of a virgin!" He also made his affections known for the Oscar-nominated actress, screaming, "I love you," and asking her to marry him. When she didn't respond and didn't break character, he became agitated, yelling, "Five seconds is too long to wait for a response!"

Security eventually arrived to escort him out, but not before he threw a bouquet of flowers onstage. Keira's co-star, Gabriel Ebert, finally broke character then, when he kicked them off the stage as the audience applauded. The show was then shut down for a short intermission.

As a result of Thursday night's unsettling interruption, Roundabout Theatre is adding extra security measures. "Roundabout takes the safety of their actors and audiences very seriously and extra security will be added beginning tonight," the theater tells ET. "For obvious reasons, we cannot comment on the exact nature of the additional security measures."

This, of course, isn't the first time a Broadway show has had some unwelcome drama. Last July, Shia LaBeouf was escorted out of a performance of Cabaretat Studio 54 in handcuffs, and was charged with criminal trespassing and disorderly conduct after allegedly being loud and disruptive during the show's first act.